Vagal terminal (intramural) ganglia
Ganglion · Cardiac plexus Pulmonary plexus Enteric plexuses
Vagal preganglionic fibres synapse in tiny ganglia within the cardiac, pulmonary and oesophageal plexuses and in the myenteric (Auerbach) and submucosal (Meissner) plexuses of the gut wall as far as the splenic flexure. Because the synapse is in the organ, the postganglionic neurone is only millimetres long.
Traced from the start
- Parasympathetic (craniosacral) outflow
- Dorsal motor nucleus of vagus and nucleus ambiguus (CN X)
- Vagal terminal (intramural) ganglia
Detail
- Cardiac ganglia
- Fat pads on the atria near the SA and AV nodes — vagal control is largely nodal, not ventricular
- Gut territory
- Oesophagus to the splenic flexure (about the distal third of the transverse colon) via the coeliac and superior mesenteric plexuses
- Enteric independence
- Vagus modulates but does not run the enteric plexuses, which coordinate peristalsis autonomously
When it goes wrong
Orthotopic heart transplant severs all vagal and sympathetic connections to the donor heart
Denervated heart: resting rate 90–110 with no respiratory sinus arrhythmia, blunted exercise response, no effect from atropine or carotid sinus massage, and silent (painless) ischaemia
Truncal vagotomy for ulcer disease removes motor supply to the antrum and pylorus
Gastric stasis unless a drainage procedure (pyloroplasty) is added; dumping and diarrhoea follow
Practise this structure
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